{"id":413,"date":"2022-05-01T10:59:23","date_gmt":"2022-05-01T02:59:23","guid":{"rendered":"http:\/\/gjweb.top\/?p=413"},"modified":"2022-05-01T10:59:26","modified_gmt":"2022-05-01T02:59:26","slug":"%e6%95%b0%e6%8d%ae%e7%b1%bb%e5%9e%8b%e5%8f%8a%e9%9a%90%e5%bc%8f%e8%bd%ac%e6%8d%a2%e5%8e%9f%e7%90%86","status":"publish","type":"post","link":"https:\/\/gjweb.top\/?p=413","title":{"rendered":"\u6570\u636e\u7c7b\u578b\u53ca\u9690\u5f0f\u8f6c\u6362\u539f\u7406"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\" id=\"\u6570\u636e\u7c7b\u578b\">\u6570\u636e\u7c7b\u578b<\/h2>\n\n\n\n<p>\u4e86\u89e3 JS \u7684\u5c0f\u4f19\u4f34 ES6 \u5f00\u59cb \u65b0\u589e\u4e86\u4e24\u4e2a\u57fa\u672c\u7c7b\u578b\uff0c\u5373\u6539\u53d8\u4e3a \u201c\u4e94\u57fa\u4e24\u7a7a\u4e00\u5bf9\u8c61\u201d<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u57fa\u7840\u7c7b\u578b<ul><li>string\u3001number\u3001boolean\u3001null\u3001undefined\u3001symbol\u3001bigint<\/li><\/ul><\/li><li>\u5bf9\u8c61\u7c7b\u578b<ul><li>Object\u5bf9\u8c61<\/li><li>Array\u3001RegExp\u3001Date\u3001Error\u3001Math\u3001ArrayBuffer&#8230;..<\/li><\/ul><\/li><\/ul>\n\n\n\n<p>\u9664\u4e86 symbol \u548c bigint \u5176\u4ed6\u7684\u6570\u636e\u7c7b\u578b\u5bf9 \u524d\u7aef\u5c0f\u4f19\u4f34\u5e76\u4e0d\u964c\u751f\uff0c\u90a3\u4ec0\u4e48\u65f6\u5019\u624d\u4f1a\u7528\u5230\u8fd9\u4e24\u4e2a\u65b0\u589e\u5c5e\u6027\u5462\uff1f<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"symbol-\u7684\u4f7f\u7528\u573a\u666f\">symbol \u7684\u4f7f\u7528\u573a\u666f<\/h3>\n\n\n\n<p>\u5f53\u6211\u4eec\u9700\u8981\u4e00\u4e2a\u552f\u4e00\u503c\uff0c\u5e76\u4e14\u8be5\u503c\u6c38\u4e0d\u91cd\u590d\u7684\u65f6\u5019<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let key = Symbol();<br>let obj = {<br> &nbsp;  &#91;key]:\"this is SybolValue\"<br>}<\/code><\/pre>\n\n\n\n<p>\u4e0a\u9762\u7684\u4ee3\u7801 \u6b64\u65f6\u7684 key \u5c31\u662f\u5bf9\u8c61 obj \u4e2d\u7684\u552f\u4e00\u5c5e\u6027\uff1b<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"bigint-\u7684\u4f7f\u7528\u573a\u666f\">bigint \u7684\u4f7f\u7528\u573a\u666f<\/h3>\n\n\n\n<p>\u5728\u4e00\u4e9b\u5f00\u53d1\u573a\u666f\u4e2d\uff0c\u4e0d\u5c11\u4eba\u4f1a\u9047\u5230\u540e\u7aef\u4eba\u5458\u4f1a\u4f20\u7ed9\u5ba2\u6237\u7aef\u4e00\u4e9b\u5927\u6570\u4f4d\u7684\u5185\u5bb9\uff0c\u8fd9\u4e9b\u5185\u5bb9\u5728\u6d4f\u89c8\u5668\u4e2d\u51fa\u73b0\u6570\u636e\u9519\u4e71\u3002 \u800c\u9488\u5bf9\u4e8e\u8fd9\u79cd\u95ee\u9898\u5e38\u7528\u7684\u65b9\u6848\u662f\u8ba9\u540e\u7aef\u5c06\u5185\u5bb9\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\u7c7b\u578b\u3002\u4f46\u662f\u5982\u679c\u8fd9\u4e2a\u5927\u6570\u9700\u5ba2\u6237\u7aef\u8ba1\u7b97\u65f6\u4efb\u7136\u4f1a\u51fa\u73b0\u6570\u636e\u9519\u4e71\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/raw.githubusercontent.com\/gongjianOnline\/ImgHosting\/main\/img\/1651371212(1).png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/raw.githubusercontent.com\/gongjianOnline\/ImgHosting\/main\/img\/1651371212(1).png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u6765\u770b\u4f7f\u7528 bigint \u540e\u7684\u8fd0\u7b97\u7ed3\u679c<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let num = BigInt(\"999984531345678951324\") \/\/999984531345678951324n<br>console.log(num - 1n) \/\/ 999984531345678951323n<br>num.toString() \/\/ 999984531345678951323<\/code><\/pre>\n\n\n\n<p>\u4e0a\u9762\u7684\u4ee3\u7801 \u4f7f\u7528 bigint \u8fdb\u884c\u5927\u6570\u8fd0\u7b97\u5c31\u4e0d\u4f1a\u51fa\u73b0\u6570\u636e\u9519\u4e71\uff0c\u4f46\u4f7f\u7528\u65b9\u5f0f\u503c\u5f97\u6ce8\u610f\u7684\u662f\u9700\u8981\u5728\u540e\u9762<strong>\u52a0\u4e0a n<\/strong><\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u5c0f\u6570\u8ba1\u7b97\u7cbe\u5ea6\u4e22\u5931\u7684\u95ee\u9898\">\u5c0f\u6570\u8ba1\u7b97\u7cbe\u5ea6\u4e22\u5931\u7684\u95ee\u9898<\/h4>\n\n\n\n<p>\u8bf4\u8d77\u6570\u636e\u9519\u4e71\u5c31\u4f1a\u8ba9\u4eba\u60f3\u5230\u5c0f\u6570\u8ba1\u7b97\u65f6\u7cbe\u5ea6\u4e22\u5931\u5982\u4f55\u5904\u7406\uff0c\u6765\u770b\u4e0b\u9762\u56fe<\/p>\n\n\n\n<figure class=\"wp-block-image\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/raw.githubusercontent.com\/gongjianOnline\/ImgHosting\/main\/img\/1651371736(1).png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/raw.githubusercontent.com\/gongjianOnline\/ImgHosting\/main\/img\/1651371736(1).png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<p>\u5728\u5c0f\u6570\u8ba1\u7b97\u65f6\u7ed9\u6240\u6709\u5c0f\u6570\u4e58\u4ee5\u4e00\u4e2a\u5341\u7684\u500d\u6570\uff0c\u6bd4\u598210\u3001100\u7b49\u8fdb\u884c\u8ba1\u7b97\uff0c\u8ba1\u7b97\u7ed3\u679c\u5728\u9664\u4ee5\u500d\u6570\u5373\u53ef\u5f97\u5230\u6b63\u786e\u7684\u7ed3\u7b97\u7ed3\u679c<\/p>\n\n\n\n<figure class=\"wp-block-image\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/raw.githubusercontent.com\/gongjianOnline\/ImgHosting\/main\/img\/1651371987(1).png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/raw.githubusercontent.com\/gongjianOnline\/ImgHosting\/main\/img\/1651371987(1).png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"\/><\/div><\/figure>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"\u9690\u5f0f\u8f6c\u6362\u89c4\u5219\u53ca\u539f\u7406\">\u9690\u5f0f\u8f6c\u6362\u89c4\u5219\u53ca\u539f\u7406<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"\u5176\u4ed6\u7c7b\u578b\u8f6c\u4e3a\u6570\u5b57\">\u5176\u4ed6\u7c7b\u578b\u8f6c\u4e3a\u6570\u5b57<\/h3>\n\n\n\n<ul class=\"wp-block-list\"><li>Number(xxx)<ul><li>\u5b57\u7b26\u4e32\u8f6c\u6570\u5b57 \u7a7a\u5b57\u7b26\u4f1a\u8f6c\u6362\u62100\uff0c\u6574\u4e2a\u5b57\u7b26\u4e2d\u53ea\u8981\u51fa\u73b0\u975e\u6570\u5b57\u7684\u5b57\u7b26\u5c31\u4f1a\u662fNAN<\/li><li>\u5e03\u5c14\u8f6c\u6570\u5b57 true : 1 ; false : 0<\/li><li>null \uff1a0<\/li><li>undefined \uff1a0<\/li><li>symbol \uff1a error<\/li><li>BigInt : \u6b63\u5e38\u7684\u6570\u503c\uff08\u4e00\u5b9a\u60c5\u51b5\u4e0b\u4f1a\u51fa\u73b0\u7cbe\u5ea6\u4e22\u5931\u95ee\u9898\uff09<\/li><\/ul><\/li><li>parseInt\/parseFloat<ul><li>\u9996\u5148\u4f1a\u628a value \u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff0c\u4ece\u505a\u5de6\u5230\u53f3\u8bc6\u522b\u5230\u7b2c\u4e00\u4e2a\u65e0\u6548\u5b57\u7b26\u4e3a\u6b62\uff0c\u628a\u524d\u9762\u7684\u6570\u5b57\u8f6c\u6362\u4e3anumber<\/li><\/ul><\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"\u5176\u4ed6\u7c7b\u578b\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\">\u5176\u4ed6\u7c7b\u578b\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u4e0d\u662f\u6240\u6709\u7684\u5bf9\u8c61\u90fd\u662f\u5b57\u7b26\u4e32\u62fc\u63a5\">\u4e0d\u662f\u6240\u6709\u7684\u5bf9\u8c61\u90fd\u662f\u5b57\u7b26\u4e32\u62fc\u63a5<\/h4>\n\n\n\n<ul class=\"wp-block-list\"><li>\u9009\u53bb\u8c03\u53d6\u5bf9\u8c61\u7684 Symbol.toPrimitive \u5c5e\u6027\u503c\uff0c\u5982\u679c\u6ca1\u6709<\/li><li>\u53bb\u8c03\u53d6\u5bf9\u8c61\u7684 valueOf \u83b7\u53d6\u539f\u59cb\u503c\uff0c\u5982\u679c\u4e0d\u662f\u539f\u59cb\u503c<\/li><li>\u518d\u53bb\u8c03\u7528 toString \u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff08\u5982\u679c\u8f6c\u6362\u4e3a\u6570\u5b57\uff0c\u5219\u56de\u8c03\u7528 Number\uff09<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>let obj = {x: 10};<br>console.log(10 + obj); \/\/\"10&#91;object Object]\"<\/code><\/pre>\n\n\n\n<p>\u4e0a\u9762\u7684\u4ee3\u7801 obj \u5bf9\u8c61\u4e2d\u6ca1\u6709 <strong>Symbol.toPrimitive<\/strong> \u5c5e\u6027\uff0c\u8c03\u53d6\u4e86 <strong>valueOf<\/strong> \u83b7\u53d6\u539f\u59cb\u503c\uff0c\u5f97\u5230\u4e86\u4e00\u4e2a {x:10}\uff0c\u7136\u540e\u8fdb\u884c\u5b57\u7b26\u4e32\u62fc\u63a5\u4e4b\u540e\u53d8\u6210 \u201d10[object Object]\u201c<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code> let obj = {<br> &nbsp; &nbsp;x: 10,<br> &nbsp; &nbsp;\/\/ obj&#91;Symbol.toPrimitive] &amp;&amp; valueOf &amp;&amp; toString<br> &nbsp;  &#91;Symbol.toPrimitive](hint) {<br> &nbsp; &nbsp; &nbsp; &nbsp;\/\/ console.log(hint); \/\/=&gt;\u201ddefault\u201c\u3001\u201dstring\u201c\u3001\u201dnumber\u201c<br> &nbsp; &nbsp; &nbsp; &nbsp;return this.x;<br> &nbsp;  }<br>};<br>console.log(10 + obj); \/\/20 <\/code><\/pre>\n\n\n\n<p>\u4e0a\u9762\u8fd9\u6bb5\u4ee3\u7801\u7ed9 obj \u6dfb\u52a0\u4e86 <strong>Symbol.toPrimitive<\/strong> \u5c5e\u6027\uff0c\u8fd4\u56de\u4e86 x \u7684\u503c\uff0c\u7ed3\u679c\u8fdb\u884c\u4e86\u6570\u5b57\u8fd0\u7b97\uff0c\u7ed3\u679c 20.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u52a0\u53f7\u4f4d\u7f6e\u51b3\u5b9a\u662f\u4e0d\u662f\u5b57\u7b26\u4e32\u62fc\u63a5\">\u52a0\u53f7\u4f4d\u7f6e\u51b3\u5b9a\u662f\u4e0d\u662f\u5b57\u7b26\u4e32\u62fc\u63a5<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>let n = \"10\";<br>+n \/\/ 10--&gt;number<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u6570\u636e\u7c7b\u578b \u4e86\u89e3 JS \u7684\u5c0f\u4f19\u4f34 ES6 \u5f00\u59cb \u65b0\u589e\u4e86\u4e24\u4e2a\u57fa\u672c\u7c7b\u578b\uff0c\u5373\u6539\u53d8\u4e3a \u201c\u4e94\u57fa\u4e24\u7a7a\u4e00\u5bf9\u8c61\u201d \u57fa\u7840\u7c7b\u578b st [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[48],"tags":[],"class_list":["post-413","post","type-post","status-publish","format-standard","hentry","category-js"],"_links":{"self":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts\/413","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=413"}],"version-history":[{"count":1,"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts\/413\/revisions"}],"predecessor-version":[{"id":414,"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts\/413\/revisions\/414"}],"wp:attachment":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=413"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=413"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=413"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}